Syria has agreed to put its chemical weapons under international control, Russian state news agency Interfax has reported. According to the agency, the Syrian foreign minister said his country was accepting the Russian proposal.
The news comes a day after US President Barack Obama said he spoke with his Russian counterpart Vladimir Putin about plans for Syria to hand over its chemical weapons.
However Obama said he was sceptical the Syrian government would follow through, the BBC reported.
David Cameron's spokesman said such a proposal could represent a "big step forward", but that the issue was one for Russia and the regime of Syria's President Bashar Assad to show that the offer is "serious and genuine".
The spokesman said that "serious questions" need to be asked about the surprise proposal put forward by Russian foreign minister Sergei Lavrov and immediately backed by Damascus on Monday.
More from The Associated Press:
Syria's foreign minister says President Bashar Assad's regime will declare its chemical weapons arsenal and sign the chemical weapons convention.
Walid al-Moallem also says Syria is ready to cooperate fully to implement a Russian proposal to put its chemical weapons arsenal under international control and it will stop producing chemical weapons.
He adds that Syria will also place chemical weapons locations in the hands of representatives of Russia, "other countries" and the United Nations.
He spoke Tuesday exclusively to the Al-Mayadeen TV station.